SummaryThis paper records inconclusive evidence obtained in the Western Highlands District of the Territory of Papua and New Guinea concerning the possible propagation by birds of sweet-potato,Ipomoea batatas(L.) Lam., seed. The Swamp Quail,Synoicus ypsilophorus, is on present evidence a plausible agent, while a number of other species cannot be ruled out of consideration. Native informants' statements that the Willie Wagtail,Rhipidura leucophrys, is responsible are reported and assessed. The possibility that migratory birds such as the Golden Plover,Charadrius dominicus, or the Peregrine Falcon,Falco peregrinus, could be responsible for the initial introduction of the sweet-potato, or for the introduction of new varieties, to the New Guinea Highlands and some other regions of the Pacific is discussed: although this seems highly improbable, it cannot be altogether discounted.It is suggested that ornithologists and aviculturalists may be able to throw light on a complex botanical and anthropological problem.